盐胁迫对转ZmPP2C2基因烟草和野生型烟草部分生理生化指标的影响

Effects of Salt Stress on Some Physiological and Biochemical Indices of Transgenic Tobacco Harboring ZmPP2C2 and Wild Tobacco

[目的]探讨外源基因的导入对植物抗盐性的影响。[方法]以转Zm PP2C2基因烟草和野生型烟草为材料,研究盐胁迫对这2种类型烟草叶片光合气体交换参数、叶绿素荧光特性及抗氧化酶活性的影响。[结果]在相同的盐浓度(150mmol/L NaCl)下,随着处理时间的延长,2种烟草的叶片净光合速率和气孔导度均呈下降趋势;最大光化学效率下降,但转基因烟草叶片降幅较小;SOD的活性均是先上升后下降,但转基因烟草下降幅度小;POD的活性、丙二醛的含量也均呈上升趋势,但转基因烟草POD活性的增加明显高于野生型烟草,而丙二醛的含量较野生型烟草低。[结论]盐胁迫下,转基因烟草叶片PSⅡ受伤害较轻,具有较高的抗氧化酶活性,其膜脂过氧化程度低于野生型烟草。

[Objective]To discuss the effects of exogenous gene introduction on the salt resistance of plants.[Method]Under salt stress,the photosynthetic gas exchange,chlorophyll fluorescence and activity of antioxidant enzymes of leaves were determined in the transgenic tobacco harboring ZmPP2C2 and the wild tobacco.[Result]Under salt stress（150 mmol/L NaCl）,the net photosynthetic rate（Pn）,stomatal conductance（Gs） and maximum photochemical efficiency of PSII（Fv/Fm） all decreased with the salt treating time in both the wild type tobacco and the transgenic tobacco.However,the level of Fv/Fm decreased less in the transgenic tobacco compared with that in the wild type tobacco.The SOD activity of the two tobacco types first rose and then declined,but it declined less in the transgenic tobacco than in the wild tobacco.The POD activity and contents of MDA increased too;however,the POD activity of transgenic tobacco increased more,and the MDA content were lower in the transgenic tobacco than in the wild tobacco.[Conclusion]The injury of PSⅡ is less in transgenic tobacco.The activity of antioxidant enzymes is higher in the transgenic tobacco than in the wild type.The extent of the membrance lipid perioxidation is smaller in transgenic tobacco than in wild type.